I think this looks pretty balanced.
If I look at the gaps...a Tank, healer, ranged, aoe....I think it could very well be a Hunter-Killer droid.
We know there are medic droids, medic could be a talent tree. Their strong armor could be used for tanking (which would mean it could be a melee droid as well). And AoE and Ranged speaks for itself.

And even if you take out the healing, that could be done by a Bounty Hunter (thinking of illegal stims and such here) it could be possible.

The Bounty Hunter wears heavy armor and on the website it is across from the Trooper. I think it's a safe bet that Trooper and Bounty hunter are counterparts.

Trooper - Bounty Hunter

And we know there's a Smuggler and some sort of sneaky Sith class (from videos and screenshots).

Smuggler - Sneaky Sith (Pirate, Spy, whatever)

The Jedi and Sith are obviously in the game and are counterparts

Jedi - Sith

The last pairing is where we have the conundrum. I'll agree that making droid as a class is limiting. Many would not want to play a droid, which would eliminate 25% of their choices. It's better to make the droid a race.

I don't think we'll see a medic class. The most recent Star Wars RPG (Saga Edition) has 5 classes: Jedi, Noble, Scoundrel, Scout and Soldier. No "healer" class, but everyone has a heroic surge mechanic to heal themselves and get back in the fight. Each class could have some kind of health recovery/damage mitigation mechanic. In addition, we know that we'll be fighting multiple weaker enemies instead of single enemies with tons of HP, so healing might not be as necessary as it has been in other MMOs.

Let's look at another source for inspiration, D&D. In D&D there are 4 roles: Defender, Striker, Controller, and Leader.

Defenders are the meleers who can soak up damage. Let's say this role is Jedi/Sith.
Strikers are single-target damage dealers. Lets say this role is Smuggler/Pirate.
Controllers are AOE damage dealers and condition givers. Let's say this role is Trooper/Bounty Hunter.

That leaves Leader as the 4th role and I think it's safe to say that this role isn't filled by any of the classes introduced so far. Perhaps an officer class is in order for both sides, to give buffs to others and perhaps get more out of companions.

Thing is, Jedi/Sith fit all the four roles depending on their class and Force powers. I guess the 4th class must be a really versatile one, since there's the Feat focused class (Trooper/BH), the Skill focused (Smuggler/Sneaky one) and the Force focused (Jedi/Sith).

Being a droid might be limiting - still, playing as HK-47 would be badass.

Well it says that the sith you play as are people going to korriban to take the trials to join to sith. (your a random force sensative going to a academy) and bounty hunters well are any race since recruited.

It may just be a hunch, but my thinking is that there wont be a healer class. Anyone else remember the medpac's from K1?

In one of the interviews I posted they mentioned something about many classes (maybe all) being able to heal in some unique, fun and epic way. Whether that means they'll all be able to use medpacks on themselves/others or have healing abilities (that may or may not be a medpack spell), we have yet to know.

i also think crafting is not goign to be a single class thing but maybe a tree thing where u can invest in it. interested to see how healing is going to... either conventional doctor class or if players can have like secondary healing powers

He be like "shut the f**k up." I be quiet. But when he leave, I be talking again.

How are ewoks badass? They are primitive little creatures from endor D:

"His name is Kettch, and he's an Ewok."
"No."
"Oh, yes. Determined to fight. You should hear him say, 'Yub, yub.' He makes it a battle cry."
"Wes, assuming he could be educated up to Alliance fighter-pilot standards, an Ewok couldn't even reach an X-wing's controls."
"He wears arm and leg extensions, prosthetics built for him by a sympathetic medical droid. And he's anxious to go, Commander."
"Please tell me you're kidding."
"Of course I'm kidding. Pilot-candidate number one is a Human female from Tatooine, Falynn Sandskimmer."
"I'm going to get you, Janson."
"Yub, yub, Commander."
―Wes Janson and Wedge Antilles

i think the sith classes and jedi classes should be dedicated to a side but all the others should get to choose their allegiance. except imperial agent of course and republic trooper. so wait that actually just leavs smuggler and bounty hunter....hmmm